Sunday, May 24, 2009

A Little Math Knowledge

Last night I went with my neighbors up to A&W to grab a little dinner. That visit provides this anecdote about math education.

We all know that fast food places don't have real cash registers anymore. No, employees now push buttons labeled with the food items and the machine magically spits out a number at the end. One might think these employees, this younger generation that's supposed to be so adept at using "technology", would know how to make these cash registers sing, or at least how to account for the use of a coupon, but one might be mistaken in that thought.

My neighbors used a coupon that provided a meal for an even $5, making their total charge $10 plus tax. The employee dutifully entered their order and then confidently announced that the price was $13 and some cents.

It didn't occur to her that anything could possibly be wrong.

My neighbors instantly got agitated, and looked at the coupon to see what they missed. I said immediately, "That's over 30% tax. Something's wrong."

Yes, California's sales tax rate is now over 8%, and Sacramento county gets its claws into us, too. But we're nowhere near 30%. Heck, that's even higher than the British Columbian tax rate with VAT added on!

Not knowing what to do, the employee called over another teenager, and they spent an inordinate amount of time trying to figure out how to enter this order. Eventually the machine came up with a figure of $10.88, which we accepted.

At a minimum, the employees should know how to use the machine; that's management's problem. However, the deeper problem is the lack of math knowledge that didn't allow for the employee to even recognize that the price was obviously off.

That's why I'm so against the use of calculators in math classes beyond mere computation. Knowing how to use the machine may be sufficient for A&W, but it's not in math class. It's not enough to know how to use a machine to get an answer in math class; students must understand the math itself.

9 comments:

Anonymous
said...

Darren,

You should consider writing some math tutorials on this blog. Simple things accompanied along with some scanned diagrams or something. For example, how to estimate the cosine of 5 without a calculator. Or even simpler things, such as tax. I for one would read them :)

I couldn't agree with you more. Would someone please tell my children's teachers? When I returned to school, I admit that I had to start with basic Algebra at 30-something, my professor refused to allow calculators in class. That was the first best thing he did for me - though embarassing to work out my multiplication in front of a class of 18 year-olds. The second best thing he did was to not let me drop the class :)

That's funny. I've gone to local fast food eateries where they employ a lot of local teenagers. Either they hit a wrong key or there's some kind of glitch in the system and their eyebrows furrow as they try to figure out how much change they should give me.

I don't know how much of this type of behavior is a reflection of poor math skills and how much is merely teeange apathy and inattentiveness. They're thinking about other things and their job is just something that gets in the way of life.

And at minimum wage, you might not have much concern over upsetting a coupon-wielding customer.My parents tried to drum into us that any job you take you should try to do well. Is that idea completely antiquated now?

What gets me in this situation is that the kid has no idea why you know the total has to be wrong. I've been treated as a mathematical genius by cashiers who have no number sense or common sense.

I remember the Girl Scout selling cookies for $2.50 a box who didn't know why a grand total ending in .25 had to be wrong. I tried to explain but she preferred to assume I'd done the multiplication in my head.